[NEW] SAML quality improvements and new config options

[pierre-lehnen-rc]

Proposed changes

• Convert SAML module to TypeScript
• Add Unit Tests to validate all aspects of the SAML operations
• Add new settings to manually configure the Request, Response and Metadata XMLs. - Closes Azure AD SAML auth context mismatch #16713
• New setting to configure the identifier format - Closes [NEW] Allowing nameIDPolicy change for saml #17502
• Expands the user fieldset setting with new functionality
• Adds possibility of choosing a custom identifier other than name and email - Closes Username or Email not updated from SAML. #15456

Issue(s)

Some bugs were fixed with those changes:

• Closes SAML channel adding does not support a multi-value "channels" claim #15852
• [FIX] Using a custom attribute for role mapping would not load multiple role names properly.
• [FIX] In some situations when using Username as identifier, the users' emails could be overwritten even if "Overwrite emails" was set to false
• [FIX] Validation of Assertion Signatures on Encrypted Responses was not working.
• [FIX] Send the LogoutRequest ID on the LogoutResponse and change the default template to include a tag around the - Closes #Fix SAML logout response issues #17879

How to test or reproduce

Screenshots

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• Improvement (non-breaking change which improves a current function)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Hotfix (a major bugfix that has to be merged asap)
• Documentation Update (if none of the other choices apply)

Checklist

• I have read the CONTRIBUTING doc
• I have signed the CLA
• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works (if applicable)
• I have added necessary documentation (if applicable)
• Any dependent changes have been merged and published in downstream modules

Changelog

• Code quality improvements adding tests and converting to TypeScript
• Add new settings to manually configure the Request, Response and Metadata XMLs
• New setting to configure the identifier format
• Expands the user fieldset setting with new functionality
• Adds the possibility of choosing a custom identifier other than name and email

Further comments

[lgtm-com]

This pull request fixes 1 alert when merging 3059ff9 into 12c11f2 - view on LGTM.com

fixed alerts:

• 1 for Useless assignment to local variable

[lgtm-com]

This pull request fixes 1 alert when merging 9c42820 into 12c11f2 - view on LGTM.com

fixed alerts:

• 1 for Useless assignment to local variable

[lgtm-com]

This pull request fixes 1 alert when merging 2e276d0 into 1b10d80 - view on LGTM.com

fixed alerts:

• 1 for Useless assignment to local variable